A notary in latin countries is not the same as a notary public in the U.S. I quote from the Wikipedia:
"Civil-law notaries, or Latin notaries, are lawyers who draft, take, and record legal instruments for private parties, provide legal advice and give attendance in person, and are vested as public officers with the authentication power of the State. Unlike notaries public, their common-law counterparts, civil-law notaries are highly-trained, licensed practitioners providing a full range of regulated legal services, and whereas they hold a public office, they nonetheless operate usually - but not always - in private practice and are paid on a fee-for-service basis. They often receive the same education as advocates at civil law, trial lawyers, or any professional litigator but without qualifications in advocacy, procedural law, or the law of evidence, analogous to solicitor training in common-law countries."
To become a notary in the DR, you must first be a lawyer and then await a vacancy in a jurisdiction (only so many notaries are allowed per jurisdiction). If there is one (there were none for ten years from 1997 to 2007), then you must pass several tests given by the Supreme Court. If you pass, then the Supreme Court will swear you in as a notary.